NPCs composing that spawngroup :

a_bile_golem (100%)

NPCs spawning around that spawngroup :
(Max range : 200)

charasis_87, range=34 (26,243,-194)

a_sepulcher_skeleton (100%)

charasis_113, range=184 (-55,99,-194)

greater_plaguebone (100%)

charasis_114, range=178 (-42,444,22)

charasis_118, range=127 (-12,147,22)

charasis_121, range=126 (12,147,22)

charasis_124, range=172 (-62,429,21)

a_bile_golem (50%)
a_sepulcher_skeleton (50%)

charasis_136, range=88 (-72,234,23)

a_bottomless_feaster (100%)

charasis_140, range=130 (131,228,23)

charasis_141, range=134 (143,275,23)

a_bottomless_feaster (100%)

charasis_142, range=88 (-72,234,22)

a_sepulcher_skeleton (100%)

charasis_144, range=170 (157,189,23)

charasis_145, range=113 (79,184,22)

charasis_146, range=49 (-6,320,22)

charasis_147, range=80 (12,353,22)

charasis_149, range=33 (-20,257,22)

charasis_150, range=148 (157,279,22)

charasis_151, range=112 (61,173,22)

charasis_152, range=70 (60,224,21)

charasis_155, range=169 (-154,224,-139)

charasis_156, range=147 (-136,242,-162)

a_sepulcher_skeleton (50%)
greater_plaguebone (50%)

charasis_157, range=109 (25,165,-194)

a_pyre_golem (50%)
a_pyre_golem (50%)

charasis_158, range=113 (-25,165,-194)

a_pyre_golem (50%)
a_pyre_golem (50%)

charasis_159, range=180 (-2,92,-188)

a_bottomless_gnawer (50%)
greater_war_boned_skeleton (50%)